The improved quality of voice communications over mobile telephone networks have contributed significantly to the growth of the wireless industry over the past two decades. Due to the interactive nature of live voice conversations, mobile telephone calls carrying such conversations require extremely low end-to-end (or mouth-to-ear) delays or latency. Compressed speech packets, referred to as speech frames, are typically received about once every 20 ms by the receiver in a typical mobile phone system. It is an industry standard approach for the decoder in such systems to decode each speech frame immediately and as quickly as possible, so that the reconstructed speech signal can be played out to the loudspeaker with little or no perceived delay.
One method used to improve the quality of the voice communications is a commonly known technique referred to as error concealment. In very simple terms, error concealment techniques are employed when a speech frame is not received, or it is received, but contains errors. These techniques attempt to conceal, mask or cover-up such errors by replacing the missing speech content with synthetic content in order to produce a more contiguous and pleasant listening experience for the user.
It is well known that the need to reduce the amount of end-to-end latency in a voice call is always at odds with quality enhancement techniques, such as error concealment and the like, due to the fact that there is simply very little time available to adequately employ such techniques. Accordingly, there is a intense need for an improved system and method to enhance the quality of wireless calls that require low end-to-end latency.